JPH10221746A - Controller for flashing light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an aperture value at the time of synchronizing a stroboscope from being affected by the error of time from giving a closing actuation to a shutter blade until actually performing closing operation at a device triggering the stroboscope at the time of closing a shutter. SOLUTION: The slits 5c, 5d and 5e of the shutter blade are detected by a photoreflector PR in a process where the shutter blade in a totally opened state is operated to be closed. The slit which is larger than an aimed aperture and also proximate is selected as a reference detecting point in accordance with distance information inputted from a range-finding circuit AF, and also delayed time (d) from passing the reference detecting point until obtaining the aimed aperture is selected. The stroboscope is triggered in timing when the delayed time (d) elapses after detecting the slit equivalent to the reference detecting point. Stroboscope synchronizing timing is controlled by the delayed time having the point of time when the shutter blade is not affected by standstill frictional force after it is actually started to be closed as a reference, so that aperture accuracy at the time of synchronizing the stroboscope is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a flash light emitting device such as a strobe, and more particularly, to a camera which obtains a still image by subjecting a subject image to photoelectric conversion like a so-called digital still camera, in particular, an exposure device. And a control device for a flash light emitting device that is optimal for a camera in which the closing operation is performed by closing a shutter blade.

[0002]

2. Description of the Related Art In recent years, digital still cameras, which use a silver halide film and record a still image as digital data without using a silver halide film, have become widespread. As this type of digital still camera, one that controls the exposure time only by controlling the operation of the image sensor without a shutter blade and one that controls the exposure time by closing the shutter blade with the shutter blade There is. Among them, those having shutter blades can easily cope with an increase in the number of pixels because the jagged image due to interlacing is eliminated without using a non-interlaced full-frame image sensor.

[0003] In general, in the case of a camera using a silver halide film, the exposure time is controlled by opening and closing a shutter blade that normally closes a photosensitive member, but in the case of a digital still camera. In order to use a monitor device such as a liquid crystal finder for framing, it is necessary for the shutter blade to open an image pickup device with power-on.
For this reason, a digital still camera having shutter blades is controlled so that exposure is started by initializing the image pickup device due to discharge of accumulated charges, and is ended by closing the shutter blades.

In general, exposure control is performed by appropriately selecting a combination of the aperture value and the exposure time, but the exposure time is controlled by the closing timing of the normally open shutter blade as described above. In this case, the shutter blades start the closing operation from the fully opened state, so that the so-called aperture effect cannot be obtained.
It is desirable to provide aperture blades separately from the shutter blades. As a diaphragm blade, a so-called iris diaphragm having five or more blades is functionally desirable. However, as is well known, the iris diaphragm has a complicated mechanism and is expensive. It is conceivable that, for example, approximately three types of large, medium, and small aperture changes can be obtained by retracting approximately several types of aperture blades into the imaging optical path.

[0005]

When photographing is performed using a flash light emitting device such as a strobe using this kind of digital still camera, the product of the photographing distance and the F value is set to the guide number. Although it is necessary, the exposure accuracy at the time of flash photography is extremely low with about three kinds of aperture values of large, medium and small as described above. Therefore, an opening forming edge is formed with respect to the shutter blade so that the aperture value changes according to the operating position, and after the shutter blade closing drive is started, a desired aperture value corresponding to the shooting distance is obtained. It is also conceivable to trigger the strobe at a timing that will be performed. However, since a very large static frictional force acts on the shutter blades and their driving members in the stationary state, there is a significant deviation in the time until the shutter blades in the stationary state start to move. Since it is necessary to perform the operation steeply compared to the operation, the time deviation from when the shutter blade is closed to when the shutter blade actually starts the closing operation causes a significant error in the actual aperture when the flash is synchronized. However, there is a problem that the exposure accuracy is significantly affected.

Of course, the above-mentioned problem can be solved by using a so-called automatic light control strobe in which the light emission amount of the strobe is controlled. However, the automatic light control strobe has an extremely high-responsive light integration circuit. It becomes expensive because of necessity, and raises the cost of the whole camera. Similarly, it is conceivable to control the strobe tuning timing by tracking the position of the shutter blade in the closing process with a subdivided photo interrupter or the like. However, in this case, a high-resolution detection means is required, and this is also required. This will increase overall costs. The present invention has been made in view of such a problem, and the time deviation between the time when a shutter blade is given a closing command and the time when the shutter actually starts the closing operation is reduced even when the cost is low. It is an object of the present invention to provide a control device of a flash light emitting device which does not affect the aperture of the flash.

[0007]

In summary, a control device for a flash light emitting device according to a first aspect of the present invention includes: an imaging optical path is supported so as to be openable and closable, and the exposure operation is terminated by blocking the imaging optical path. A shutter blade having an opening forming edge for regulating the aperture of the imaging optical path corresponding to a traveling position; a flash light emitting means having a constant light emission amount emitted by a trigger signal; and at least a closing operation of the shutter blade A blade position detecting means for detecting that the shutter blade has passed one or a plurality of predetermined detection points, at least: a distance information inputting means for inputting photographing distance information, and a photographing distance information inputted by the distance information inputting means. Based on the above 1
Or a detection point selection means for selecting a plurality of detection points as reference detection points: the blade position detection means detects the selected reference detection point based on photographing distance information input by the distance information input means. Delay time setting means for setting a delay time from when the trigger signal is applied to the flash light emitting means to the flash light emitting means: the delay time setting means starts from the timing at which the blade position detecting means detects the reference detection point. The above object is achieved by providing trigger means for applying the trigger signal to the flash light emitting device at a timing when the set delay time has elapsed.

According to a second aspect of the present invention, there is provided a control device for a flash light-emitting device, comprising:
Imaging means arranged on an image plane on which field light is imaged by the imaging optical system: an imaging optical path from the imaging optical system to the imaging means is supported so as to be openable and closable, and accumulates photoelectric conversion charges. With imaging means: an imaging optical path from the imaging optical system to the imaging means is supported to be openable and closable, and the exposure operation is terminated by blocking the imaging optical path, and the aperture of the imaging optical path corresponding to a traveling position. Blade having an opening forming edge for regulating the light emission: a flash light emitting means emitting a constant amount of light by a trigger signal; and: the shutter blade detects at least one predetermined detection point at least at the time of closing operation of the shutter blade. A blade position detecting means for detecting the passage; a distance information input means for inputting photographing distance information; and Or a detection point selection means for selecting a plurality of detection points as reference detection points: the blade position detection means detects the selected reference detection point based on photographing distance information input by the distance information input means. Delay time setting means for setting a delay time from when the trigger signal is applied to the flash light emitting means to the flash light emitting means: the delay time setting means starts from the timing at which the blade position detecting means detects the reference detection point. Trigger means for applying the trigger signal to the flash light emitting device at the timing when the set delay time has elapsed.

The control device for a flash light emitting device according to a third aspect of the present invention further includes: a diaphragm means for restricting an opening area of the imaging optical path stepwise by one or a plurality of apertures; Is characterized in that a point that is closed and driven to a position corresponding to one or more apertures regulated by the aperture means is one or more detection points detected by the blade position detection means.

That is, according to the present invention, the timing at which the shutter blade has passed through the predetermined detection point after the shutter blade has been driven to close is the starting point, and the timing at which the delay time according to the shooting distance has elapsed from the starting point. The triggering of the flash light emitting device is performed by controlling the timing of triggering the flash light emitting device after the shutter blade and its driving mechanism are released from the static friction force, and a closing command is issued to the shutter blade. An error does not occur in the actual aperture value during tuning of the flash light emitting device due to a time deviation from when the shutter blade actually starts moving. Further, since the trigger timing of the flash light emitting device is controlled by both the detection of the position of the shutter blade after the start of the closing drive and the delay time from the detection point, the resolution of the photo interrupter for detecting the position of the shutter blade is low. It is possible to reduce the overall cost without any problem in control.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a state in which a power supply of a camera body of an imaging apparatus according to the present invention is turned off, and FIG. 2 is a sectional view showing a periphery of a moving magnet. In FIG. 1, reference numeral 1 denotes an upper base plate, 2 denotes a middle base plate, and 3 denotes a base plate. In FIG. 1, the upper base plate 1, the middle base plate 2 and the base plate 3 are virtually shown by the same dashed line. An exposure opening AP that forms an image pickup optical path is formed in a central portion of these ground plates.
Reference numerals 4 and 5 denote shutter blades for opening and closing the exposure opening AP.
The shutter blades 4 and 5 are swingably supported by pins 1a and 1b implanted on the back surface of the upper base plate 1, respectively. The shutter blades 4 and 5 in this embodiment have opening forming edges 4a and 5a for regulating the opening area of the exposure opening AP corresponding to the operation position, and shield the exposure opening AP when no power is supplied. In state.

Reference numeral 6 denotes a moving magnet for driving the shutter blades 4 and 5 to open and close. FIG. 2 is a sectional view, and FIG. 3 is an enlarged plan view of FIG.
The reference numerals of the components of the moving magnet 6 are not particularly shown in FIG. 1, but can be understood by referring to FIGS. The moving magnet 6 has a cylindrical casing 6a.
The coil frame 6b is fixed to the inside of the coil frame 6b.
The coil 6c is wound along the longitudinal direction as shown in FIG. A two-pole magnet 6e is rotatably supported on a shaft 6d provided inside the coil frame 6b, and an output pin 6f protruding outside the magnet 6e is connected to the upper ground plate 1.
The shutter blades 4 and 5 penetrate the middle base plate 2 and are engaged with long holes 4b and 5b (see FIG. 1) formed in the shutter blades 4 and 5, respectively.

The operating range of the output pin 6f is the pins 1c, 1 made of a ferromagnetic material such as iron implanted on the upper base plate 1.
d. Output pin 6f in the initial state
The pin 1c is magnetically attached and held in the state shown in FIGS. 1 and 3, but when a positive pulse current is supplied to the coil 6c in this state, the upper side in FIG.
A magnetic field that becomes a pole is formed, the magnet 6e rotates counterclockwise about the shaft 6d, and the output pin 6f comes into contact with the pin 1d and stops. Since the output pin 6f magnetically attaches the pin 1d, even if the supply of the positive pulse current is cut off, the output pin 6f is maintained in a state where the pin 1d is magnetically attached. When a negative pulse current is supplied to the coil 6c from a state in which the output pin 6f magnetically attaches the pin 1d, a magnetic field having a lower N pole in FIG. 3 is formed around the coil frame 6b. 6e rotates clockwise around the shaft 6d, and the output pin 6f comes into contact with the pin 1c and stops. Since the output pin 6f magnetically attaches the pin 1c, even if the supply of the negative pulse current is cut off, the output pin 6f is maintained in a state where the pin 1c is magnetically attached.

In this embodiment, it is assumed that three types of aperture control, large, medium and small, are performed, and the fully opened state of the exposure opening AP corresponds to the large aperture. The medium and small apertures are obtained by moving the aperture blades 7 or 8 into the exposure openings AP, respectively. First, the aperture blade 7 corresponding to the medium aperture is swingably supported by a pin 1e implanted in the upper base plate 1, and an opening 7 corresponding to the medium aperture is provided at the tip of the aperture blade 7.
a is formed. Reference numeral 9 denotes a moving magnet serving as a driving source for rotating the diaphragm blade 7. The structure of the moving magnet 9 is basically the same as that of the moving magnet 6 already described, and an output pin 9f is formed on the diaphragm blade 7. With the elongated hole 7b. In the present embodiment, the moving magnet 9 rotates clockwise around the shaft 9d by supplying a positive pulse current until the output pin 9f contacts the ferromagnetic pin 1f. By supplying a current, the pin rotates counterclockwise about the axis 9d until it comes into contact with the ferromagnetic pin 1g. When the output pin 9f of the moving magnet 9 is in contact with the pin 1f, the opening 7a formed in the diaphragm blade 7 is substantially concentric with the opening 7a.

Next, the aperture blade 8 corresponding to the small aperture is swingably supported by a pin 1h planted on the upper base plate 1, and an opening 8 corresponding to the small aperture is provided at the tip of the aperture blade 8.
a is formed. Reference numeral 10 denotes a moving magnet serving as a drive source for rotating the aperture blade 8, and the structure of the moving magnet 10 is basically the same as that of the moving magnet 6 already described.
Are engaged with a long hole 8b formed in the aperture blade 8.
In this embodiment, the moving magnet 10
Is connected to output pin 1 by supplying a positive pulse current.
0f rotates clockwise around the axis 10d until it comes into contact with the ferromagnetic pin 1i, and supplies a negative pulse current to rotate counterclockwise around the axis 10d until it comes into contact with the ferromagnetic pin 1j. To rotate. An opening 8 a formed in the aperture blade 8 is provided with an output pin 1 of the moving magnet 10.
When 0f is in contact with the pin 1i, the opening 8a and the exposed opening AP are substantially concentric.

A photoreflector PR detects slits 5c, 5d and 5e formed in the shutter blade 5, respectively. In the present embodiment, when the shutter blades 5 are closed until the opening forming edges 4a, 5a formed in the shutter blades 4, 5 form an opening equivalent to the aperture AP corresponding to a large aperture, the slit 5c is set to the photo reflector PR.
When the shutter blade 5 closes until the opening forming edges 4a and 5a formed on the shutter blades 4 and 5 form an opening equivalent to the opening 7a corresponding to the medium aperture, the slit 5d is detected by the photo reflector PR. An opening forming edge 4a formed on the shutter blades 4 and 5
When the shutter blade 5 closes until the opening 5a forms an opening equivalent to the opening 8a corresponding to a small diameter, the slit 5e
Is detected by the photo reflector PR.

FIG. 4 is a block diagram of a control system according to the present embodiment. Reference numerals 4 and 5 denote the above-described shutter blades 4 and 5, and reference numerals 7 and 8 denote the above-described aperture blades 7 and 8. , 6,9,1
0 indicates the above-described moving magnets 6, 9, and 10,
PR indicates each of the photoreflectors described above. or,
R indicates a reflecting surface, and AF indicates a known distance measuring circuit for measuring a subject distance. Reference numeral 11 denotes a photographing lens, reference numeral 12 denotes a CCD as an example of an image pickup means, and reference numeral 13 denotes a storage process of an image signal output from the CCD 12, an input process of an output signal of the photoreflector PR, and a distance measurement circuit AF. A signal processing circuit for inputting distance information, etc., 14 a shutter release switch, 15 a main switch, 16 a microcomputer, and 17 a shutter drive for supplying a driving signal to a moving magnet 6 for driving the shutter. A diaphragm driving circuit for supplying drive signals to the moving magnet 9 and the moving magnet 10 for driving the diaphragm; an electronic shutter control circuit 19 for controlling charge accumulation and discharge of the CCD 12;
Indicates a strobe selection switch for selecting use of the strobe 20.

Reference numeral 22 denotes a data table which is a feature of the present embodiment. The data table 22 has slits 5c, 5d, and 5d serving as detection points corresponding to subject distance information input from the distance measuring circuit AF.
5e is configured by a memory in which data for selecting and setting a delay time is stored. That is, when the light emission amount of the strobe and the sensitivity of the imaging unit are fixed, the aperture value at which the proper exposure is obtained in the strobe shooting is uniquely determined by the shooting distance. Also, there is a large deviation between the time when the shutter blades 4 and 5 are issued a closing command and the time when the shutter blades 4 and 5 have a desired diameter due to the static frictional force of the shutter blades 4 and 5. After the shutter actually starts closing, the time from when the slit 5c formed in the shutter blade 5 is detected by the photoreflector PR to when a desired aperture intermediate between the large aperture and the medium aperture is obtained, or The time from when the slit 5d formed in the blade 5 is detected by the photoreflector PR to when a desired aperture intermediate between the medium aperture and the small aperture is obtained, or the slit 5e formed in the shutter blade 5 is changed to the photoreflector PR. Is detected and the time from when the desired diameter smaller than the small diameter is obtained is stable without being affected by the static friction force. Therefore, in the present embodiment, a data string indicating which of the slits 5c, 5d, and 5e is detected and how much delay time is required to obtain an appropriate aperture for the input subject distance information is a data table. 22
And this data is read out using the subject distance information as a parameter.

Next, the above items, flowcharts of FIGS. 5 and 6, time charts of FIGS. 7 and 8, FIGS.
The operation of the present embodiment will be described in detail with reference to a plan view showing a state change of 0. First, in the initial state, the mechanism is shown in FIG.
In the state shown in FIG. When the main switch 15 is turned on, the program starts, and the microcomputer 16 controls the electronic shutter control circuit 19 to control the CCD 12.
, And controls the shutter drive circuit 17 to supply a positive pulse current to the moving magnet 6. (Steps S2 and S3)

When a positive pulse current is supplied to the moving magnet 6, the output pin 6f is connected to the shaft 6d.
Around the pin 1d until it comes into contact with the pin 1d. When the output pin 6f contacts the pin 1d, the output pin 6f magnetically attaches the pin 1d, so that the position of the output pin 6f is maintained even in a non-energized state after the positive pulse current falls. In this way, when the output pin 6f rotates counterclockwise from the state shown in FIG.
Since the shutter blades a and 5a are engaged with each other, the shutter blade 4 turns left around the shaft 1a, and the shutter blade 5 turns right around the shaft 1b to open the exposure opening AP. FIG. 9 shows a state where the shutter blades 4 and 5 have opened the exposure openings AP.

The distance measuring circuit AF outputs distance information indicating the distance to the subject to the signal processing circuit 13, and this distance information is read into the microcomputer 16 via the signal processing circuit 13 (step S4). . Also, CCD1
When the shutter blades 4 and 5 open the exposure aperture AP and the CCD 12 is exposed to the field light as described above, the output of the CCD 12 is applied to the microcomputer 16. Can be Then, the microcomputer 16 measures the field brightness from the output of the CCD 12, calculates an appropriate aperture value and shutter time, and waits for the release switch 14 to be turned on (step S5). Then, when the release switch 14 is turned on in step S9, the process branches according to the aperture value calculated in step S4 (step S10).

When the aperture value to be used is a medium aperture, the microcomputer 16 controls the aperture drive circuit 18 to supply a positive pulse current to the moving magnet 9 (step S11). Turn clockwise around 9d until it comes into contact with pin 1f.
Since f is magnetized, the clockwise position is maintained even in the non-energized state in which the positive pulse current has fallen. Then, along with the clockwise rotation of the moving magnet 9, the diaphragm blade 7 also rotates clockwise about the shaft 1e, and the opening 7a narrows the exposed opening AP to the middle diameter. Note that FIG. 9 shows that the opening 7a is exposed in this manner.
Is shown in a state where is narrowed down to the middle diameter. When the aperture value used is small, the microcomputer 16 controls the aperture driving circuit 18 to control the moving magnet 10.
Is supplied (step S12), and the moving magnet 10 turns clockwise around the shaft 10d until the output pin 10f contacts the pin 1i to magnetize the pin 1i. The right-handed position is maintained even when the power is turned off. And the moving magnet 10
The aperture blade 8 also rotates clockwise about the axis 1h with the clockwise rotation of the aperture 8a to narrow the exposed aperture AP to a small diameter. still,
Although the state of the small aperture is not shown, the aperture blade 8 restricts the opening of the exposure aperture AP instead of the aperture blade 7 of FIG. 9 and will be easily understood. Further, when the aperture value to be used is a large aperture, the operation of narrowing down the exposure aperture AP is not performed, and the process immediately proceeds to step S13. That is, in this case, the aperture value becomes the aperture value without changing the aperture of the exposure aperture AP.

When the aperture value is determined in this manner, the microcomputer 16 controls the electronic shutter control circuit 19 to discharge the electric charge stored in the CCD 12 (step S).
13). Accordingly, the CCD 12 starts a new charge accumulation operation at the rising timing of the control signal, and this timing is the start timing of the effective exposure second.
Next, in step S14, the microcomputer 16 determines whether or not to perform flash photography based on the state of the flash selection switch 21.

First, the case where the strobe 20 is not used will be described. Note that the first half of the time chart of FIG. 6 shows the time when the strobe 20 is not used. Since the proper exposure time when the strobe is not used has already been calculated in step S5, the microcomputer 16 releases the charge stored in the CCD 12 in step S13, and after the exposure time calculated in step S5 elapses (step S5). S15) The shutter drive circuit 17 is controlled to supply a negative pulse current to the moving magnet 6 (Step S16). When a negative pulse current is supplied to the moving magnet 6, the output pin 6f is moved to the pin 1 around the shaft 6d.
Rotate clockwise until it touches c. When the output pin 6f contacts the pin 1c, the output pin 6f is
, The position of the output pin 6f is maintained even in the non-energized state after the negative pulse current has fallen. When the output pin 6f rotates clockwise from the state shown in FIG. 9 in this manner, the shutter blade 4 rotates clockwise about the axis 1a, and the shutter blade 5 rotates counterclockwise about the axis 1b to cover the exposure opening AP. I do. Therefore, in the case of large-diameter photography in which the aperture diameter is determined by the exposure aperture AP, the total area of the hatched portion ABC in FIG. 7 corresponds to the effective exposure amount, and in the case of medium-diameter photography in which the aperture diameter is determined by the aperture 7a of the diaphragm blade 7. 7, the total area of the hatched portion BC in FIG. 7 corresponds to the effective exposure amount, and in the case of small-diameter photography in which the aperture diameter is determined by the opening 8a of the diaphragm blade 8, the area of the hatched portion C in FIG. Would be equivalent.

When the shutter blades 4, 5 cover the exposure aperture AP in this manner, the microcomputer 16 controls the signal processing circuit 13 to take in the output of the CCD 12 (step S24), and the signal processing circuit 13 converts the image signal. For example, writing to a storage device such as an external memory card or the like completes one shooting operation. When one photographing operation is completed in this way, the microcomputer 16 prepares for photographing the next frame as follows. That is, the microcomputer 16 determines whether or not the aperture blade 7 or 8 has been used in step S25. A negative pulse current is applied to the moving magnet 9 if the aperture blade 7 is used, and to the moving magnet 10 if the aperture blade 8 is used, and the aperture blade 7 or the aperture blade 8 is plotted. After returning to the initial state shown in FIG.
After returning to 3, the shutter blades 4 and 5 are opened, and in step S9, the process waits for the release switch 14 to be turned on.
Needless to say, the moving magnets 9 and 10 maintain the state shown in FIG. 1 even after the negative pulse current is stopped by the magnetic force between the output pins 9f and 10f and the pins 1g and 1j. When it is detected in step S6 that the power switch 15 has been turned off while waiting for the release switch 14 to be turned on in this way, the shutter drive circuit 17 is controlled in step S7 to control the moving magnet 6 to apply a negative voltage. A pulse current is applied, and the shutter blades 4 and 5 are driven to close to complete the exposure operation. The control operation after the power switch 15 is turned off is executed by, for example, supplying power from a capacitance circuit such as a capacitor (not shown).

Next, the use of the strobe 20 will be described. Note that the latter half of the time chart in FIG. The distance to the subject has already been read in step S4. Therefore, the microcomputer 16 accesses the data table 22 based on the subject distance information read in step S4, and after detecting which of the slits 5c, 5d, and 5e formed in the shutter blade 5 is detected by the photoreflector PR, the strobe is used. Is read out (step S1).
7). The slit determined in this way corresponds to a reference detection point. Next, the microcomputer accesses the data table 22 based on the subject distance information read in step S4, and how much delay time elapses after the target slit among the slits 5c, 5d, and 5e is detected by the photo reflector PR. Flash 2 when you do
It is read out whether to trigger 0 (step S18). still,
The time chart of FIG. 7 (FIG. 8 shows an enlarged view of this portion) shows that the strobe 20 is turned on at the timing when the delay time d elapses after the slit 5d is detected by the photo reflector PR.
Triggering is shown.

In this manner, when the slit serving as the reference detection point and the delay time are determined, the microcomputer 16
Supplies a negative pulse current to the moving magnet 6 by controlling the shutter driving circuit 17 so that the shutter blades 4, 5
Is performed (step S19). Referring to FIG. 8, after the shutter blades 4 and 5 are started to be closed, the shutter blades 4 and 5 are opened until the opening areas formed by the opening forming edges 4a and 5a are substantially equal to the exposure openings AP. The slit 5c is detected by the photo reflector PR at the timing when the closing operation of the shutter blades 4 and 5 proceeds, and the shutter blades 4 and 5 are closed until the opening area formed by the opening forming edges 4a and 5a becomes substantially equal to the opening 7a of the diaphragm blade 7. The slit 5d is detected by the photo reflector PR at the timing when the closing operation proceeds, and the closing operation of the shutter blades 4 and 5 proceeds until the opening area formed by the opening forming edges 4a and 5a is substantially equal to the opening 8a of the diaphragm blade 8. At this timing, the slit 5e is detected by the photo reflector PR, and the photo reflector PR generates a pulse signal. The microcomputer 16 generates the photoreflector PR 2
The first pulse signal (ie, slit 5 serving as a reference detection point)
When a pulse signal corresponding to d is received via the signal processing circuit 13 (step S20), the process waits until the delay time d read in step S18 elapses.

When the elapse of the delay time d is confirmed in step S21, a trigger signal is applied to the strobe 20 in step S22 to cause the strobe 20 to emit light. Accordingly, the strobe 20 emits light at a timing when a desired aperture in the middle between the middle aperture and the small aperture is obtained. Thereafter, when the time required for the shutter blades 4 and 5 to completely close has elapsed (step S23), the process proceeds to step S24 to read an image signal in the same manner as when the strobe is not used.

In the above description, an example in which the present invention is applied to the strobe control of a digital still camera using a CCD as an image pickup device has been described. However, if the strobe is tuned in the closing process of the shutter blade, a so-called silver halide is used. It goes without saying that the present invention can be applied to strobe control of a camera using a film.

[0030]

As described above, according to the present invention, the timing at which the shutter blade passes a predetermined detection point after the shutter blade is driven to close is set as a starting point, and a delay corresponding to the shooting distance from the starting point. Since the flash light emitting device is triggered at the time when the time has elapsed, the timing for triggering the flash light emitting device after the shutter blade and its driving mechanism are released from the static friction force is controlled. An error does not occur in the actual aperture value at the time of tuning of the flash light emitting device due to a time deviation from when the close command is issued until the shutter blade actually starts moving, and the exposure accuracy at the time of flash photography is extremely stable. . Further, since the trigger timing of the flash light emitting device is controlled by both the detection of the position of the shutter blade after the start of the closing drive and the delay time from the detection point, the resolution of the photo interrupter for detecting the position of the shutter blade is low. It is possible to reduce the overall cost without any problem in control.

[Brief description of the drawings]

FIG. 1 is a plan view of an imaging device according to an embodiment of the present invention in an initial state.

FIG. 2 is a cross-sectional view of the moving magnet 6 shown in FIG.

FIG. 3 is an enlarged plan view of the moving magnet 6 shown in FIG.

FIG. 4 is a block diagram of a control system of the imaging apparatus according to the embodiment of the present invention.

FIG. 5 is a first half of a flowchart showing a control operation of the control system shown in FIG. 4;

FIG. 6 is a latter half of a flowchart showing a control operation of the control system shown in FIG. 4;

FIG. 7 is a time chart showing operation timings of the control system shown in FIG. 4;

FIG. 8 is a partially enlarged view of the time chart shown in FIG. 7;

FIG. 9 is a plan view showing a state where the embodiment shown in FIG. 1 is in a middle stop state and shutter blades are fully opened.

10 is a plan view showing a state where the closing operation of the shutter blade has progressed from the state shown in FIG. 9 until the shutter blade reaches a middle diameter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper ground plate 1c, 1d, 1f, 1g, 1i, 1j Pin 4, 5 Shutter blade 6 Moving magnet 6f Output pin 7 Middle aperture diaphragm blade 7a Opening 8 Small aperture diaphragm blade 8a Opening 9 Moving magnet 9f Output pin 10 Moving Magnet 10 f Output pin 11 Lens 12 CCD 16 Microcomputer 20 Strobe 21 Strobe selection switch 22 Data table AP Exposure aperture AF Distance measuring circuit PR Photoreflector R Reflective surface

Claims (3)

[Claims] An imaging optical path is supported so as to be openable and closable, and an exposure operation is terminated by blocking the imaging optical path, and an opening forming edge for regulating the aperture of the imaging optical path corresponding to a traveling position is formed. A shutter blade, a flash light emitting unit that emits a constant amount of light by a trigger signal, and a blade position detecting unit that detects that the shutter blade has passed one or more predetermined detection points at least when the shutter blade is closed. Distance information input means for inputting shooting distance information; detection point selecting means for selecting the one or more detection points as reference detection points based on the shooting distance information input by the distance information input means; After the blade position detecting means detects the selected reference detection point based on the photographing distance information input by the distance information input means, the flash light emission is started. A delay time setting means for setting a delay time until a trigger signal is applied to the optical means; and a delay set by the delay time setting means starting from a timing at which the blade position detecting means detects the reference detection point. And a trigger means for applying the trigger signal to the flash light emitting device at a timing when time has elapsed. 2. An imaging optical system for imaging incident light on a predetermined imaging surface, imaging means arranged on an imaging surface on which object light is imaged by the imaging optical system, and the imaging optical system An imaging optical path which is supported to be openable and closable in an imaging optical path from the camera to the imaging means, and which is capable of opening and closing an imaging optical path from the imaging optical system to the imaging means; A shutter blade formed with an opening forming edge for controlling the aperture of the imaging optical path corresponding to a traveling position while closing the exposure operation by blocking, and a flash light emitting unit emitting a constant amount of light by a trigger signal; A blade position detecting means for detecting that the shutter blade has passed one or a plurality of predetermined detection points at least during a closing operation of the shutter blade, a distance information inputting means for inputting photographing distance information; A detection point selection unit that selects the one or more detection points as a reference detection point based on the photographing distance information input by the information input unit, and a photographing distance information input by the distance information input unit,
Delay time setting means for setting a delay time from when the blade position detecting means detects the selected reference detection point to when a trigger signal is applied to the flash light emitting means; and Trigger means for applying the trigger signal to the flash light emitting device at a timing when a delay time set by the delay time setting means has elapsed from a timing at which the detection point was detected as a starting point. Control device. 3. A control device for a flash light emitting device according to claim 1, further comprising a diaphragm means for regulating an opening area of said imaging optical path stepwise by one or a plurality of apertures, wherein said shutter blade is said diaphragm. A point which is closed and driven to a position corresponding to one or a plurality of apertures regulated by the means is one or a plurality of detection points detected by the blade position detecting means.